Commensurate and Incommensurate Helix Configuration in Hexatic Liquid Crystals with Chiral Molecules

(Received 28 April 1995, revised 6 July 1995, accepted 8 September 1995)

Abstract
In hexatic I ^* and F ^* liquid crystals the director and the net of the bonds defined by the bond-orientational order are spiraling about the axis normal to the smectic layers. A continuum elastic distortion theory of liquid crystals predicts the existence of two possible configurations. If the commensurate configuration is stable, the director and the bond orientation are locked together causing an uniform helix for both degrees of freedom. In the incommensurate state the director alignment differs from the alignment of the bonds so that two helices occur. A transition from the commensurate to the incommensurate state is possible if a coupling parameter passes a critical value.